Novel synthesis of oxa[9]helicenes by Lawesson’s reagent-mediated cyclization of helical quinone derivatives
摘要:
New oxa[9]helicenes which possess one furan ring have been readily prepared by reactive helical quinone with Lawesson's reagent or phosphorus pentasulfide in good yields. The versatility of this protocol has been demonstrated with various substituted helical quinones. (C) 2011 Elsevier Ltd. All rights reserved.